I suspect you’d want to dam
I suspect you’d want to dam your piece using fiber strips and bullseye brick dams. You need to put the fiber paper between the glass and dams. While I’ve never worked with float glass and have not made any slabs similar to what you’re planning, I *think* you’d create the texture by fusing it on some fiber paper or fiber blanket that you’ve built designs and texture into. More than likely though, the texture was introduced using a sandblaster after the layers were fused together since its matte and so extremely textured. I’d experiment with the fiber paper thickness and designs with small pieces of float glass first to make sure it gives you the desired results. Finally, one other consideration since you’re making this as a table top, you’ll need to consider whether its tempered glass or not. Tabletops take a lot of stress and wear & tear…. Just some personal thoughts and considerations.